1. Field of the Invention
This invention relates to an improved process for the preparation of iodine pentafluoride.
2. Description of the Prior Art
It is known to produce iodine pentafluoride (IF.sub.5) by reacting gaseous fluorine with solid iodine crystals; see Schumb et al., "Iodine Heptafluoride," Industrial and Engineering Chemistry, Vol. 42, July 1950, pp. 1383-1386. One of the disadvantages of this process is that the bed of solid iodine crystals serves as a poor heat transfer medium. This causes hot spots to develop in the reaction zone leading to poor temperature control. Additionally, iodine heptafluoride (IF.sub.7) formed by the reaction between the IF.sub.5 product vapors and the excess flourine is greatly aggravated by these hot spots in the reaction zone. Another disadvantage is the plugging of the process lines downstream from the reaction zone by the recrystallization of iodine.
A current commercial method for the production of IF.sub.5 is disclosed in Tepp, U.S. Pat. No. 3,367,746 in which gaseous fluorine is reacted with iodine dissolved in an inert solvent such as the IF.sub.5 product. The temperature of the reaction is critical and must be maintained below 98.degree. C, the boiling point of the IF.sub.5 solvent. The chief disadvantage of this process is the requirement for a large number of reaction vessels and auxiliary equipment in order to dissolve the iodine in the IF.sub.5 solvent and to return the resulting iodine solution to the reaction zone.